[mutter] clutter/actor: Cancel delayed timelines on removal

[Marco Trevisan <marcotrevi src gnome org>]

commit c9c53cb55fd6e782c50f36da1e2adbf28111a660
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Fri Sep 20 16:21:00 2019 +0200

    clutter/actor: Cancel delayed timelines on removal
    
    Delayed clutter timelines might be removed while they are still in the
    process of being executed, but if they are not playing yet their delay
    timeout won't be stopped, causing them to be executed anyway, leading to a
    potential crash.
    
    In fact if something else keeps a reference on the timelines (i.e. gjs), the
    dispose vfunc delay cancellation won't take effect, causing the timelines to
    be started and added to the master clock.
    
    To avoid this, expose clutter_timeline_cancel_delay() function and call it
    if a timeline is not playing but has a delay set.
    
    Fixes https://gitlab.gnome.org/GNOME/mutter/issues/815
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/805

 clutter/clutter/clutter-actor.c    | 2 ++
 clutter/clutter/clutter-private.h  | 2 ++
 clutter/clutter/clutter-timeline.c | 2 +-
 3 files changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/clutter/clutter/clutter-actor.c b/clutter/clutter/clutter-actor.c
index f600a838c..0aa77e3d6 100644
--- a/clutter/clutter/clutter-actor.c
+++ b/clutter/clutter/clutter-actor.c
@@ -19484,6 +19484,8 @@ transition_closure_free (gpointer data)
 
       if (clutter_timeline_is_playing (timeline))
         clutter_timeline_stop (timeline);
+      else if (clutter_timeline_get_delay (timeline) > 0)
+        clutter_timeline_cancel_delay (timeline);
 
       /* remove the reference added in add_transition_internal() */
       g_object_unref (clos->transition);
diff --git a/clutter/clutter/clutter-private.h b/clutter/clutter/clutter-private.h
index a34cae44b..d1da84c8e 100644
--- a/clutter/clutter/clutter-private.h
+++ b/clutter/clutter/clutter-private.h
@@ -315,6 +315,8 @@ gboolean        _clutter_run_progress_function  (GType gtype,
                                                  gdouble progress,
                                                  GValue *retval);
 
+void            clutter_timeline_cancel_delay (ClutterTimeline *timeline);
+
 G_END_DECLS
 
 #endif /* __CLUTTER_PRIVATE_H__ */
diff --git a/clutter/clutter/clutter-timeline.c b/clutter/clutter/clutter-timeline.c
index bb4f77f06..88b76be4b 100644
--- a/clutter/clutter/clutter-timeline.c
+++ b/clutter/clutter/clutter-timeline.c
@@ -424,7 +424,7 @@ clutter_timeline_set_custom_property (ClutterScriptable *scriptable,
     g_object_set_property (G_OBJECT (scriptable), name, value);
 }
 
-static void
+void
 clutter_timeline_cancel_delay (ClutterTimeline *timeline)
 {
   g_clear_handle_id (&timeline->priv->delay_id, g_source_remove);